| Title |
External Condensation Heat Transfer Coefficients ofR22 Alternative Refrigerants and R134a According tothe Saturated Vapor Temperature Change on an Enhanced Tube |
| Keywords |
Condensation heat transfer ; 응축 열전달 ; Alternative refrigerant ; 대체냉매 ; HTCs ; 열전달계수 ; R22, R410A, R407C, R134a |
| Abstract |
In this study, external condensation heat transfer coefficients(HTCs) are mea-sured on a low fin tube and Turbo-C tubes at the saturated vapor temperature of 30℃, 39℃, and 50℃ for R22, R410A, R407C and R134a with the wall subcooled at 3∼8℃. The HTCs of all refrigerants decreased as increasing the saturation temperature from 30℃ to 50℃. This trend is due to better thermodynamic properties of the liquid phase at low temperature. Beatty and Katz's prediction yielded a 20.0% deviation for the low fin tube data. The heat transfer enhancement factors for the 26fpi low fin tube and Turbo-C tubes are 4.0∼5.5 and 3.0∼8.1 respectively for the refrigerants tested. Finally the performance of Turbo-C tube is better than that of the low fin tube. |